This invention relates to long-pulsewidth lasers and more particularly, to a power supply for a long-pulsewidth laser flashlamp.
Since the invention of the laser, short-pulsewidth solid-state lasers have been developing rapidly. With the development of the high power continuous wave (CW) Nd: YAG laser, the output power of the laser went from several watts, in a single-rod operation, to 1,000 watts in a multiple-rod operation. This type of CW laser has broad applications in material cutting, drilling, annealing, and heat treatment of metals.
Because of various short comings with short-pulse lasers and CW lasers, a long-pulsewidth pulsed Nd: YAG laser with high average power has been in development in recent years. This laser has an average output power of several hundred watts. With recent developments, this type laser now has an average output power of 400 watts and a peak output power of 10,000 watts.
There are two types of power supplies for driving laser flashlamps. One is a conventional charger and inductor-capacitor forming network; while the other utilizes a rectified current source, a high-frequency switch, and an inductor-capacitor filter. With the former type of power supply, one problem encountered is in driving a laser flashlamp with pulses in excess of approximately 2 milliseconds (2 ms). To overcome this problem, multiple capacitor-inductor networks, connected in series, are used. Such systems tend to be inflexible, heavy, and expensive. Compared with this former type system, the latter is compact and has a high degree of flexibility. Therefore it is applied to industrial laser applications as a pumping power supply. However, this latter type power supply is quite expensive and technically complex.